Processing of photographic film



March 29, 1960 C. M. TUTTLE IN V EN TOR.

(1 5mm M. TUTTLE HTTOENEVS United States; Patent PROCESSING OF PHOTOGRAPHIC FILM Clifton M. Tuttle, Huntington, N.Y., assignor, by mesne assignments, to Specialties, Inc., Syosset, N.Y., a corporation of New York Application January 31, 1957, Serial No. 637,417

2 Claims. (CI. 95-14) This invention relates to the processing of photographic film, paper, or other light-sensitive material, and has particular reference to an improved method and apparatus for this purpose in which the latent images formed by exposure of a strip of the photographic material can be developed and fixed rapidly in a simple and inexpensive manner.

In photographic recording operations, of which the recording of oscillograph traces is typical, a length of photographic film or paper material is exposed and wound on a take-up roll. The length of the photographic material may be short (two or three feet) or long (one hundred feet or more), and the width of the recording material also varies with the kind of equipment used and the type of record which is required. Photographic materials varying in width between 16 mm. and inches are in common use. The linear velocity of the photographic recording material through the camera alsodepends upon the record requirement and may vary from about one inch per minute to about several feet per second. Also, the kinds of photographic material used in these recording operations are numerous. The sensitivity characteristics of the photographic material must be chosen according to the exposure requirements. Thus, for very fast recording with a consequent high writing speed of the record, the most sensitive type of photographic emulsion must be used on the photographic material, whereas at the other end of the scale with very slow writing speed a very insensitive type of emulsion is indicated.

Regardless of the variations in length, width, recording speed and material characteristics mentioned above, the rolled-up record must be passed through processing operations before the record becomes of any use. The processing operations as conventionally performed comprise developing, fixing, washing and drying of the photographic material, either in a tray or in a specially constructed machine. I

The processing operations mentioned above, as performed heretofore, involve numerous disadvantages. A major disadvantage is time delay. For example, with one specific type of recording material which may be regarded as very easy to process, a time lapse of one-half hour for processing of one hundred feet of material is considered very fast. With other photographic materials which are more difiicult to process, a processing time of two or three hours is customary. Another disadvantage is that the conventional processing equipment is very bulky and usually requires a photographic dark-room for its use. Further disadvantages are that a different type of equipment and difierent chemical solutions are required for each different type of photographic material; large quantities of expensive solutions are required, which must be accurately controlled in temperature and concentration and must be constantly replenished or frequently discarded; and the processing operations can be performed only by highly skilled personnel.

The present invention has for its principal object the 2,930,302 Patented Mar. 29, 1960 "ice provision of an improved method and apparatus for processing photographic material, which overcomes or minimizes the above-noted disadvantages.

In my copending application Serial No. 449,962, filed August 16, 1954, I have disclosed an improved method and apparatus for accomplishing the above-noted object but in a somewhat diiferent manner than the present invention.

According to the present invention, a length or strip of the sensitized photographic material is exposed to provide a series of latent images on the sensitized surface of the strip. From the exposure station, the strip is passed partly around a working roller, by means including a take-up roll, the sensitized surface of the strip facing away from the worldng roller. A strip of absorbent material saturated with a developing solution is moved partly around the working roller while in contact with the exposed sensitized surface of the photographic strip, and this movement of the saturated strip is effected so as to produce movement thereof relative to the sensitized surface as the two strips move partly around the working roller. In this way, a sliding action is obtained between the saturated absorbent strip and the photographic strip as they pass through an are around the working roller, whereby the developing solution is intimately contacted with the sensitized surface to develop the latent images rapidly and uniformly.

In the preferred construction of the new apparatus, a second absorbent strip is saturated with a fixing (or stabilizing) solution and is moved partly around the working roller while in contact with the sensitized surface of the photographic strip at a region thereof located between the take-up roll and the contact of the first absorbent strip (saturated with the developing solution) with the emulsion surface of the photographic strip. This second absorbent strip is also moved relative to the sensitized surface as the strips move partly around the working roller. Accordingly, the sensitized surface of the exposed film strip or other photographic material from the exposure station is subjected first to a sliding contact with the absorbent strip saturated with developing solution and then to a sliding contact with the absorbent strip saturated with the fixing solution, after which the processed film may pass directly to the take-up roll. The sliding contact of each absorbent strip with the sensitized surface of the photographic strip may be effected by moving the absorbent strip in the opposite direction to the photographic strip or in the same direction at a different linear speed, as the two strips move partly around the working roll, against which they are pressed together to enhance the contact.

Preferably, each absorbent strip is delivered from a supply roll to a take-up roll by way of a pair of idler rollers disposed in closely spaced relation to the working roller, so that the photographic strip and the absorbent strip pass in superimposed relation between each idler roller and the working roller and over a substantial arc around the working roller. By proper spacing of the idler rollers from the working roller, the pressure of the sliding contact between the absorbent strip and the sensitized surface can be controlled to the desired amount.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which the single illustration is a vertical sectional view of a preferred form of the new apparatus.

Referring to the drawing, the numeral 10 designates a housing which is light-tight except for a window W at the upper rear portion. Below this window, the housing 10 has an enlarged base portion 10a. At its front portion, the housing 10 has a tubular projection 11 containing the usual lens 12. The object to be photographed a through its shaft 18.

is here shown as a cathode ray tube from which an image is projected through the lens 12 to the exposure station S in the housing 10. i

A strip of photographic material P, such as a photographic film, is wound 'on a supply spool 14 rotatably mounted in the housing 10. From this spool 14', the film strip F extends downwardly through the exposure station S and then under and partly around a working roller 15. The latter roller is mounted for rotation on a shaft 15a in the housing. From the working roller 15, the film strip F extends upwardly and over a guide roll 1% and thence to a take-up roll 17 rotatably mounted on a shaft The take-up roll 17 may be driven in the usual manner The working roller 15 is also driven, either through movement of the film strip F by take-up roll 17 or directly through the shaft 15a of the working roller. In either case, the take-up roll 17 constitutes a means for moving the film strip F along a path through the exposure station S and partly around the working roller 15, with the sensitized surface of the strip F facing away from the roller 15.

A strip of absorbent material A, such as paper, is wound on a supply spool 20 in the lower part of the housing. This strip is saturated with a developing solution and extends from the supply spool 20 to a pair of idler rollers 21 which serve as a means for guiding the saturated strip A partly around the lower portion of the working roller 15 while in contact with the sensitized surface of the film strip F From'the guiding rollers 21, the absorbent strip A passes to a take-up roll 22 which is driven in any suitable manner through a shaft 22a.

A second strip of absorbent material B is wound on a supply spool 23 in the lower part of the housing. The strip B is saturated with a fixing (or:stabilizing) solution and extends from the spool 23 to a pair of idlerrollers 24 which constitute a means for guiding thesaturated strip partly around the working roller 15 while in contact with the sensitized surface of film strip F. From the guiding rollers 24, the strip'B passes to take-up roll 25 driven in any suitable manner through a shaft 25a.

It will be observed that the guide rollers 21 and 24 'maintain the absorbent strips A and B, respectively, in

contact with the sensitized surface of the exposed film strip F 'over arcs of substantial length extending partly around the lower peripheral portion of the working roller 15. Also, the guide rollers 24 maintain the absorbent-strip B in contact with the film strip F at a region thereof located between the take-up roll 17 and'the region of contact between the film strip F and the first absorbent strip A. Thus, the film strip F from the exposure station S is first subjected to the action of the developer solution carried by the absorbent strip A and is then subjected'to the action of the fixing solution carried by the absorbent strip B.

The absorbent strips A and 'B are drawn from their respective supply spools 29 and 23 to their respective takeup rolls 22 and 25 in such a manner as to produce movement of these strips relative to the film stripF as the strips move partly around the working roller 15. As illustrated, the means for so moving the saturated strips A and B comprise the drive shafts 22a and 25a of the respective take-up rolls 22 and 25, these rolls being so arranged that the corresponding strips A and B move partly around the working roller 15 in the direction opposite to that of the film strip F.- It will be understood, however, that the rolls 22and 25 may constitute the supply rolls while aeaaeee the rolls 20 and 23 constitute the take-up rolls, in which case the desired relative movement can be obtained by operating the take-up rolls so that the corresponding abproduces a sliding contact with the sensitized surface of thevfilmstrip F during movement of the latter around the working roller 15. As a result, the developing and fixing solutions are more intimately and uniformly contacted with the sensitized surface ofthe exposed film strip, thereby enabling faster processing'while conserving the quantity of the solutions used in the processing.

It will be understood that the various driven rolls or rollers maybe driven with a step-by-step movement by conventional mechanisms for this purpose. .Preferably, however, they are driven continuously, the exposure of the successive frame sections of tbefilm strip F at the exposure station S being controlled in any conventional manner to accommodate such continuous movement.

I claim:

1. In a photographic recording apparatus having an exposure station, the combination of a working roller, means including a take-up roll for moving a strip of photographic material having a sensitized surface along a path through said station and partly around the working roller, with said sensitized surface facing away from the roller, twopairs of guide rollers spaced circumferentially along the periphery of the working roller and substantially parallel to the working roller, the guide rollers being spaced from said sensitized surface, a pair of absorbent strips each extending partly around a pair of the guide rollers between said last rollers and the working roller, the absorbent strips engaging said sensitized surface over spaced arcuate portions thereof, respectively,

each arcuate portion extending partly around the working roller, developing and fixing solutions saturating the absorbent strips, respectively, means for moving each absorbent strip in one direction relative to said sensitized surface asthe photographic strip moves along said path, whereby said solutions are wiped upon said arcuate portions of the sensitized surface, and supply rolls-on which the respective absorbent strips are wound, said moving means for the absorbent strips including a take-up roll for each absorbent strip. 7

2. The combination according to claim 1, in which said moving means for the absorbent strips are operable to;move each absorbentstrip in the direction opposite to the direction 'of movement of the sensitized surface Where the absorbent strip engages said surface.

References Cited in the file of this patent UNITED STATES PATENTS Great"Britain Aug. 11,1193? 

